Year: 2025
Type: article
Abstract: Barium strontium titanate (BST) thin films are distinguished for their ferroelectric behavior which makes them highly promising for optical and microwave applications, but there is a lack of studies in the important terahertz (THz) frequency range. In this work, we report the deposition of high‐quality BST films by physical vapor deposition at high temperatures and its application in tunable THz metadevices. The Ba 0.6 Sr 0.4 TiO 3 film exhibits a full width at half maximum of 0.57° in high‐resolution X‐ray diffraction (HR‐XRD) spectroscopy, a real dielectric constant of 140 at 0.2 THz. By integrating interdigitated electrodes (IDEs) of varying periodicities, we systematically investigated their impact and identified a 100 µm electrode separation as the optimal electrode separation for maximizing THz response modulation. A metasurface using Ba 0.6 Sr 0.4 TiO 3 thin film as the active material working in reflection mode has been designed using finite‐difference time‐domain (FDTD) simulation, and the fabricated metadevice experimentally demonstrated a remarkable resonance shifts of up to 5.5 GHz under applied voltage. These findings underscore the potential of BST for reconfigurable intelligent metasurfaces and future electrically tunable THz device applications.
Source: Small Structures
Institutions: Agency for Science, Technology and Research, Centre National de la Recherche Scientifique, Institute of Materials Research and Engineering, Institut d'Electronique, de Microélectronique et de Nanotechnologie, Université de Valenciennes et du Hainaut-Cambrésis, Université Polytechnique Hauts-de-France, National University of Singapore, Singapore Synchrotron Light Source
Language: English
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,110
Awards: G4761912992, G506366594, G6380015898
OpenAlex ID: W4416540971